Northern flying squirrels range from
about 7 to 10 inches in length, not including the tail,
which is generally about 80% as long as the body. They
have silky gray and cinnamon brown fur, with white-tipped
and gray-based belly hairs. Both sexes are similar in
size and coloration. The most distinguishing feature of
the flying squirrel is a web of furred skin along both
sides of the body extending from the foreleg to the
hindleg and ending on the tail.

Distribution and Habitat

The northern flying squirrel ranges
from the treeline in Alaska and Canada southward to
northern California and Colorado, and from central
Michigan and Wisconsin into northern North Carolina and
Tennessee. It is most commonly found in areas dominated
by conifers, but are also found in deciduous and mixed
forests.

Habits and Behaviors

Strictly nocturnal, northern flying
squirrels are active for about two hours beginning an
hour after sunset, and again for about one-and-a-half to
two hours before sunrise. They rest by day in hollows in
trees and will also use roof spaces, outbuildings and
bird nesting boxes.

Female northern flying squirrels are
territorial, but males are not. Groups of up eight adults
and juveniles may share a single nest, especially during
the winter.

Diet

Like most squirrels, the northern
flying squirrel feeds on nuts, acorns, fungi, and
lichens, supplemented by fruits, buds, sap, and the
occasional insect and bird egg. Food is often hoarded in
order to ensure a steady supply during the winter months.

Reproduction

Breeding takes place between March and
May, with one to six young born after a gestation period
of 37 to 42 days. Young are weaned after about two
months, and are able to live on their own after about
three months. Sexual maturity is reached at about one
year of age.

Flight Abilities

One could say that flying squirrels do
not truly fly because they do not have wings like birds
or bats, and such a statement would be somewhat true.
However, to say that a flying squirrel simply glides from
one tree to another would actually be quite far from the
truth. In fact, the only real difference between
birds/bats and flying squirrels is that the former are
capable of powered flight, whereas the latter engage in
controlled flight without wing beats.

Before becoming airborne a flying
squirrel leans its head first to one side then to the
other, getting a "fix" on the distance and
direction it must travel to its desired landing spot.
After determining where it wishes to land, the squirrel
leans forward, pushes with its hind legs and spreads all
four legs at right angles to the body so the flying
membranes form a near-perfect square. In flight, the
squirrel uses its tail as a balance and a rudder to help
keep it on course. In addition, by dropping the
legs of one side, to give added lift to the membrane on
the other side, the squirrel can bank or turn sharply. It
can also dive steeply and use the speed to rise steeply
at the end of the dive.

On landing, the squirrel immediately races around to
the other side of the tree, a precaution against attack
from a predator while still recovering from the landing.

Although most glides are simple, from one tree to
another in a direct line, flying squirrels have been seen
to make right-angled turns, lateral loops, spiral ascents
and other aerobatics. They have even been seen to change
their minds in mid-flight, turn completely around and
land again on the exact spot from which they had just
taken off.

Young flying squirrels make their first short flights,
under the close supervision of their mothers, at about
one month of age.